In the production of food products it may in some circumstances be advantageous or desirable to arrange a second food product on a substrate formed by at least one first food product, this second food product being placed as a layer on the first food product. The second food product can for instance have a colour differing from that of the first food product in order to thus impart a decorative effect to the combination. Another possibility is that a desired effect, for instance a conserving effect, can be obtained by the different material properties. The second food product can be arranged in different forms, such as for instance in the form of an image, an icon, a text or a pattern, although a full or partial coating of the second food product is also possible. The first food product can herein be a substantially solid substance, such as chocolate, or a gelatinous substance such as a dessert or yoghurt, while the second food product consists, at least during dispensing, of a liquid or a liquid emulsion such as yoghurt, mayonnaise, sauce, oil and so forth.
Devices for applying a decoration to a food product are per se known. WO 01/93691 describes a device in which a number of nozzles are placed in an array for the purpose of applying a decoration in the form of a bitmap by means of spraying. The device has per nozzle a dispensing means which comprises a cylinder with a piston for dispensing a predetermined quantity of the liquid. It is further proposed to place the array at an oblique angle to a direction of movement of the first food product in order to thus increase the possible resolution of a decoration to be applied.
Such a device has various drawbacks. Due to its complex construction with narrow feed channels, cylinders and pistons, it is difficult to clean, which represents a problem because of the strict hygiene requirements in for instance the processing of food products. The described device further functions slowly as a result of the required alternating pattern of movement of the piston during dispensing of the liquid. In addition, there is a possibility of the liquid solidifying in the channels, whereby the device requires a high level of maintenance. This essential maintenance is increased still further here due to the great wear of the plunger and nozzle as a result of the moving parts.
An alternative for dispensing a liquid food product is known from ES 1 191 528, which describes a device for filling containers for liquid substances. This device however also has the drawback that dispensing of an accurate, very small quantity of liquid, in the order of magnitude of a droplet, is not possible herewith due to the large liquid storage capacity of the supply and discharge channel and the high resistance the channel provides to the liquid. Due to the force exerted thereon the membrane is further subject to great wear, which makes the embodiment susceptible to wear. Moreover, ES 1 191 528 does not disclose one device having a plurality of dispensing openings.
WO 2006/041222 describes a body-insertable apparatus, clearly not intended nor suitable for controlled dispensing of a liquid to a substrate. The apparatus comprises a balloon member, which is expandable by adding a medium via communication pipe. The balloon acts to generate a changing volume of a chamber in order to generate a liquid flow out of the apparatus of into the apparatus. However, the dispensing opening in the apparatus is continuously uncovered, so the liquid in the chamber cannot be placed under pressure.
It is therefore an object of the present invention to provide a device for dispensing a liquid, such as a food product, which obviates at least one of the above stated drawbacks, or provides a usable alternative.